The present invention relates to a counter-rotating axial-flow fan used for cooling the inside of an electric appliance or the like.
Japanese Patent Application Publication No. 2004-278371 (Patent Document 1) and Japanese Patent No. 3904595 (Patent Document 2) disclose a counter-rotating axial-flow fan including a housing which includes a housing body and a motor support frame. The housing body includes an air channel having a suction opening on one side in an axial line direction and a discharge opening on the other side in the axial line direction. The motor support frame is disposed in the central portion of the air channel. In this counter-rotating axial-flow fan, a first impeller that is rotated by a first motor is disposed within a first space that is defined between the motor support frame in the housing and the suction opening. Further, a second impeller that is rotated by a second motor is disposed within a second space that is defined between the motor support frame in the housing and the discharge opening. The first impeller rotates in a direction opposite to a rotating direction of the second impeller. The motor support frame includes a support frame body disposed in the central portion of the air channel, and a plurality of blades that connect the support frame body and the housing body. One of the webs includes therein a lead wire guide path that communicates with an internal space of the support frame body and is opened at an outer surface of the housing body. The lead wire guide path guides a plurality of lead wires that supply electric power to the first and second motors.
The housing is constituted from first and second divided housing units that are coupled through a coupling structure. The first divided housing unit includes a first housing-body half-portion and a first support-frame half-portion. The first housing half-portion has the suction opening at one end thereof and contains the first space therein. The first support-frame half-portion is obtained by dividing the motor support frame into two along a virtual reference dividing plane extending in a radial direction of rotary shafts orthogonal to the axial line direction. The second divided housing unit includes a second housing-body half-portion and a second support-frame half-portion. The second housing-body half-portion has the discharge opening at one end thereof and contains the second space therein. The second support-frame half-portion is obtained by dividing the motor support frame into two along the virtual reference dividing plane. The first support-frame half-portion and the second support-frame half-portion respectively include a first support-frame-body half-portion and a second support-frame-body half-portion, which are obtained by dividing the support frame body into tow so that the first and second support-frame-body half-portions are abutted onto each other on the virtual reference dividing plane. The first support-frame half-portion and the second support-frame half-portion also respectively include a plurality of first web half-portions and a plurality of second web half-portions, which are obtained by dividing the plurality of webs into two along the virtual reference dividing plane. The first and second web half-portions, which constitute the web including therein the lead wire guide path (lead-wire guide web), each include a pair of side walls. The pair of side walls of the first web half-portion and the pair of side walls of the second web half-portion (first and second lead-wire guide-web half-portions) are abutted onto each other on the virtual reference dividing plane when the first and second web half-portions are combined with each other.
In the conventional counter-rotating axial-flow fan, however, lead wires tend to run off from the first and second lead-wire guide-web half-portions when combining the first and second divided housing units. Consequently, the lead wires are easily sandwiched between the side walls of the first lead-wire guide-web half-portion and the side walls of the second lead-wire guide-web half-portion opposed to the first lead-wire guide-web half-portion when assembling the divided housing units. Thus, it becomes impossible to combine the first and second divided housing units.